Diaspora AI is actually a very interesting story. I added a bunch of new features so the AI can take advantage of glide and sidethrust, for example... but if you turn all of these on, the AI becomes nearly impossible to beat. The raiders all use a dumbed-down version of the AI that does use the new features... but overall, very rarely.
Another thing we had to solve was that even with this, the AI was STILL too hard in some ways. Freespace AI has a bizarre concept of accuracy where how accurate the AI is depends mostly on how long the ship has been targeting you but completely ignores how evasive your flying is. The AI would literally pick a random point X meters off your port bow (that would result in a miss), then aim perfectly at that miss-spot as you dive and swoop to dodge. Your evasiveness simply didn't matter at all... and this could get very frustrating in Diaspora where a few seconds of sustained fire is enough to destroy any fighter.
By the way, the hardest AI in the game is actually found in the second training mission with the fight against Obit. Obit uses an AI class tuned for fighter dueling: it's easier to dodge (the AI has a higher "lag" compensating for its target changing velocity vectors) but is also much, much more aggressive, using glide and sidethrust to basically try to keep you in the gunsights as much as possible. The result, IMHO, is an AI opponent that really puts the pressure on and feels like a major threat.
I'll stop now, but this is something I put a lot of time and effort into over the course of Diaspora's development and can blabber on about all day given half a chance.
If anyone is curious about the effects various AI.tbl and AI_Profiles.tbl settings will have on how the AI dogfights, I'd be happy to help.